I observed that, on turning the box on in the morning, it responds well to the remote, I'd even say is working normal.

However, with the box on throughout the day, towards the evening, it becomes intermittently unresponsive as described above. I suspect this could be either a thermal issue whereby the temperature of the box internals is impacting its ability to receive the remote's signals. Or that there is a software bug/regression in the most recent update, which includes a problem, like a memory leak, that manifests only if the box has been on for some time. Though having turned off and turned on the box, the problem prevails.